Creation of Secondary Porosity in Dolostones by Upwelling Basement Water in the Foreland of the Alpine Orogen

Figure 7

(a) Secondary quartz filling an anhydrite mould in the Trigonodus Dolomit (BEN 825.11 m). (b) The quartz contains tiny, distributed inclusions of pyrite and relict anhydrite, indicating that the quartz precipitated during anhydrite dissolution and thus is associated with the formation of the anhydrite-dissolution pores (BEN 825.11 m). (c) Second-stage calcite clogging anhydrite moulds in the Muschelkalk (BOZ 81.90 m). (d) Calcite in fractures (SLA 1170.83 m). (e) Intergrowths of kaolinite and calcite filling an anhydrite mould (SLA 1135.29 m). (f) Intergrowths of barite (arrowheads) and calcite filling an anhydrite mould (SLA 1164.33 m). (g) Anhydrite occasionally replaces calcite within moulds and fractures in the Muschelkalk (calcite stained with Alizarin Red; SLA 1123.83 m). (h) Saddle dolomite filling anhydrite moulds in the deeply buried Muschelkalk. Saddle dolomite postdates secondary quartz and associated minerals (BER 2189.11 m) (a, b, h: crossed-polarized, transmitted-light microscopy; e–g: plane polarized, transmitted-light microscopy; c, d: reflected-light photograph of drill core).

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